(1) Field of the Invention
The present invention relates to an optical disk drive for recording and reproducing information with respect to an optical disk. More specifically, the present invention relates to a locking mechanism used when a tray on which an optical disk is placed is inserted into a chassis.
(2) Description of the Related Art
In general, an optical disk drive installed in an electronic device has a tray held in a drive body (chassis) so that the tray is automatically inserted into and ejected from the drive body or the chassis. The tray is ejected from the chassis to place an optical disk thereon, and is inserted into the chassis again. In this way, the optical disk is loaded into the drive body. The tray includes a spindle motor for rotating the optical disk, and an optical pickup movably attached in the radial direction of the optical disk to record or reproduce information by irradiating a laser beam to a recording surface of the optical disk.
When the tray is inserted into the chassis, a lock arm on the side of the tray is engaged and locked with a lock shaft on the side of the chassis. Thus, the tray is closed. The engagement between the lock arm and the lock shaft is released by pressing an eject button. Thus, the tray is opened. Here, in order to release the lock arm, a movable piece absorbed by a solenoid is removed from the solenoid. However, once removed from the solenoid, the movable piece no longer automatically returns to its initial position (reset state). For this reason, it is necessary to perform an operation (a reset operation) for returning the movable piece to the initial position at the time of the insertion of the tray into the chassis. Thus, the tray is provided with a reset arm for performing the return operation of the movable piece. The reset arm rotates when a projecting portion (a boss) provided on the side of the chassis is engaged with an end portion of the reset arm.
In order to normally perform the return operation of the movable piece, the engaging amount (overlapping amount) between the engaging boss and the reset arm should be set within a predetermined range. When the engaging amount is small, the return operation of the movable piece in the insertion of the tray is insufficient, and the lock operation of the tray fails. However, because of a clearance provided between the tray and the chassis for smooth insertion and ejection of the tray, it has been difficult to manage the engaging amount between the engaging boss and the reset arm.
To address the above problem, JP-A No. 66485/2007 discloses a configuration designed to avoid the failure of the engagement between the tray and the chassis. Here, there is provided an eject lock mechanism for engaging the chassis and the tray, a rail for movably holding the chassis and the tray, a rail holding portion provided in the tray to hold the rail, and a rail guide provided in the chassis to hold the rail. The rail guide has a projecting portion. When the tray is inserted into the chassis, the projecting portion is located on the side of a spindle motor rather than the rail, as well as on the side of the insertion direction of the tray rather than the rotation center of the spindle motor.
The JP-A No. 66485/2007 describes the effect as follows. When the tray is inserted into the chassis, it is possible to control a motion space of the tray, which extends in the direction perpendicular to the insertion direction of the tray and extends in the direction parallel to a principle plane of the chassis, within a certain range. In other words, it is possible to control the insertion condition of the tray having the eject lock mechanism, within a certain range. As a result, when the tray is inserted into the chassis, it is possible to avoid the failure of the engagement between the tray and the chassis that occurs due to the insertion condition of the tray.